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With the McIntosh preamp AND the McIntosh MC452, you might actually be at the very limit of what this combination can do. If you wanted to keep working with your components without starting from scratch, one idea that I would put forth is to see if you can have somebody bring a Pass Labs "XA" full Class A amplifier into your system and see how it sounds. I think the Pass "XA" amp would have much better resolution and excitement than the McIntosh MC452, but still have enough thickness and "controlled dynamics" to prevent the Focal speaker from getting out of control.
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If you really wanted to choose another speaker, the only one that comes to mind is to look at Wilson Audio. They are extremely high resolution and transparent. But in the end, you might still be fighting the "laid back" sound of the McIntosh electronics. Nothing bad about McIntosh, but it does have its own sonic signature.
Legacy Focus might also be good with the fast ribbon tweeters, but again, it really depends what you're looking for.